The Classifications and Status columns on the validation report are the two most important fields for understanding your verification results when you validate email addresses.
The output values for the Classifications field are just four and well-defined:
- Deliverable
- Risky
- Undeliverable
- Unknown
Instead, there are many possible values for the Status field: a description with general recommendations for most customers of each value is listed here below.
We strongly encourage you to consider your individual needs when grouping the Status into different Classifications and evaluating non-definitive or risky results: you could either choose to reject all results whose value is not "Success" or accept some of them.
Generic status codes
Success
Valid email. Verification was completed to mailbox level. No high-risk factors detected. Safe to send mail.
Syntax status codes
UnmatchedQuotedPair
Invalid email format, a quoted pair within a quoted word is not closed properly.
UnexpectedQuotedPairSequence
Invalid email format, an unexpected quoted pair sequence has been found within a quoted word.
InvalidWordBoundaryStart
Invalid email format, a new word boundary start has been detected at an invalid position.
InvalidCharacterInSequence
Invalid email format, an invalid character has been detected in the provided sequence.
UnbalancedCommentParenthesis
Invalid email format, the number of parenthesis used to open comments is not equal to the one used to close them.
DoubleDotSequence
Invalid email format, an invalid sequence of two adjacent dots has been found.
InvalidLocalPartLength
Invalid email format, the local part of the e-mail address has an invalid length.
InvalidFoldingWhiteSpaceSequence
Invalid email format, an invalid folding white space (FWS) sequence has been found.
AtSignNotFound
Invalid email format, the at sign symbol (@), used to separate the local part from the domain part of the address, has not been found.
InvalidEmptyQuotedWord
Invalid email format, an invalid quoted word with no content has been found.
InvalidAddressLength
Invalid email format, the email address has an invalid total length.
DomainPartCompliancyFailure
Invalid email format, the domain part of the email address is not compliant with the IETF standards.
IspSpecificSyntaxFailure
Invalid email format, the email syntax is invalid as per specific requirements for the internet service provider.
Disposable status codes
DomainIsWellKnownDea
High-risk email type, the email address is provided by a well-known disposable e-mail address provider (DEA). We strongly suggest removing DEAs from your lists.
MailboxIsDea
High-risk email type, the mailbox for the email-address is disposable / throw-away. We strongly suggest removing this kind of emails from your lists.
MailExchangerIsWellKnownDea
High-risk email type: our neural networks determined the external mail exchanger is a disposable email address provider (DEA). We strongly suggest removing DEAs from your lists.
DNS status codes
DomainDoesNotExist
Invalid email address, the domain of the e-mail address does not exist.
DnsQueryTimeout
Email failed to validate, a timeout has occurred while querying the DNS server(s) for records about the e-mail address domain. Retrying the validation may result in a definitive response.
DnsConnectionFailure
Email failed to validate, verification failed because of a socket connection error occurred while querying the DNS server. Retrying the validation may result in a definitive response.
DomainIsMisconfigured
Invalid email address, the domain of the email address does not have any valid DNS records and couldn't accept messages from another host on the Internet.
SMTP status codes
SmtpConnectionTimeout
Invalid email address, a timeout has occurred while connecting to the mail exchanger which serves the e-mail address domain.
SmtpConnectionFailure
Invalid email address, a socket connection error occurred while connecting to the mail exchanger which serves the email address domain.
SmtpDialogError
Invalid email address, an error occurred while communicating with the mail exchanger which serves the email address domain.
LocalEndPointRejected
Failed to validate, the external mail exchanger rejected the local endpoint. Retrying the validation may result in a definitive response.
Mailbox status codes
MailboxDoesNotExist
Invalid email address, the mailbox for the email address does not exist.
MailboxConnectionFailure
Failed to validate, a connection error occurred while validating the mailbox for the e-mail address. Retrying the validation may result in a definitive response.
LocalSenderAddressRejected
Failed to validate, the external mail exchanger rejected the local sender address. Retrying the validation may result in a definitive response.
MailboxValidationTimeout
Failed to validate, a timeout occurred while verifying the existence of the mailbox. Retrying the validation may result in a definitive response.
MailboxTemporarilyUnavailable
Failed to validate, the requested mailbox is temporarily unavailable. This does not indicate that the mailbox exists but is often a response returned by mail exchangers with greylisting enabled. Retrying the validation using a higher validation level may result in a definitive response.
ServerDoesNotSupportInternationalMailboxes
Invalid email address, the external mail exchanger does not support international mailbox names. To support this feature, mail exchangers must comply with RFC 5336 and support and announce both the 8BITMIME and the UTF8SMTP protocol extensions.
MailExchangerIsHoneypot
Invalid email address, the external mail exchanger hides a honeypot (spam trap).
Catch-all status codes
CatchAllValidationTimeout
Failed to validate, a timeout occurred while verifying fake e-mail address rejection for the mail server. Retrying the validation may result in a definitive response.
ServerIsCatchAll
High-risk email type, the external mail exchanger accepts fake and non-existent e-mail addresses; therefore the provided e-mail address MAY not exist. The existence of the individual mailbox cannot be verified. Retrying the validation may result in a definitive response.
CatchAllConnectionFailure
Failed to validate, a connection error occurred while verifying the catch-all settings on the external mail server. Retrying the validation may result in a definitive response.
Duplicate removal/scrub status codes
Duplicate
The email address appears to be duplicated with another entry which appears previously in the same validation job.
Miscellaneous status codes
UnhandledException
Failed to validate, one or more unhandled exceptions have been thrown during the verification process. Retrying the validation may result in a definitive response.